The best solution for the long-term is to patiently train the dogs to go elsewhere. Or, you could install at least a temporary physical barrier. In the short-term, repellents would seem to be the only solution. There are a number of commercial products available (Hinder or Ropel), but they do need to be applied and reapplied according to the label instructions in order to be effective. Most large garden centers stock a variety of them.